Geography Climate and Vegetation

Climate & natural vegetation

Introduction:

Climate is the average weather conditions of a region over a considerable period of time (i.e. 30 years)

Various classifications of climates

Natural vegetation refers to all the types of plants which grow naturally.

Primary vegetation is those plants found at a location originally

Secondary vegetation is those plants that recolonise (i.e. naturally) an area after it is abandoned

CLIMOGRAPH:

graphical representation of a climate in terms of temperature & precipitation

mean mthly temp;

- absolute fig

- constant/variable

- seasonality

total mthly precipitn

- absolute fig

- constant/variable

- seasonality

CLIMOGRAPH:

arbitrary classification of figures:mean temp:

> 300C : very hot

20 - 300C : warm - hot

10 - 200C : moderately warm

0 - 100C : cold

< 00C : very coldTemp range: diurnal & mthly / ann. small : 0 - 30C / 0 - 30C moderate : 4 - 70C / 4 - 70C large

: 8 - 120C / 8 - 150C very large: >120C / >150C

CLIMOGRAPH:

arbitrary classification of figures:precipitation: annual / mthly

very high : >2000 / 120

high : 1000 - 2000 /100 - 120

moderate : 750 - 1000 / 75 - 100

low (arid) : 250 - 750 / 25 - 75

very low : 0 - 250 /(desert) 0 - 25

CLIMOGRAPH:

derive mean annual temperature & total annual precipitation if they are not given

EQUATORIAL CLIMATE

Distribution

EQUATORIAL CLIMATE

Distribution

close to the Equator (100N - 100S)

Amazon Basin, Northern Zaire Basin, & parts of Southeast Asia like Singapore, Malaysia & most parts of Indonesia

EQUATORIAL CLIMATE

Characteristics Spore

1. High mean annual temperature(26.90C)2. High mean mthly temperature (26-280C)3. Very small annual temp. range (20C)

4. Moderate diurnal temp. range ( 60C)5. High to very high annual rainfall (2344mm)6. High to very high mthly rainfall(>150mm)

EQUATORIAL CLIMATE

EQUATORIAL CLIMATE

EQUATORIAL CLIMATE

Reasons:

1. High & constant mthly temperature equatorial location

high angle of incidence;

not affected by tilt of Earth’s axis constant duration & intensity of

sunlight

2. Moderate diurnal temp. range moderating effect of thick clouds

EQUATORIAL CLIMATE

Reasons:

3. High to very high mthly & annual rainfall large body of water & frequent convectional rain; some places also have monsoon rain

TROPICAL RAINFOREST

Distribution:

TROPICAL RAINFOREST

Distribution:

TROPICAL RAINFOREST

Distribution:

~ Amazon Basin

~ Zaire Basin

~ much of Central America

~ much of Southeast Asia

TROPICAL RAINFOREST

Structure:

•some very tall trees (40 - 48 m) known as emergents form the emergent layer•canopy layer is formed from the interlocking crowns of most trees (25 - 40m); presence of lianas & epiphytes •understorey layer is formed by shorter trees (5 - 25 m); presence of lianas & epiphytes

TROPICAL RAINFOREST

Structure:

•shrub layer consists of shrubs, ferns & saplings (2 - 5m)

•ground layer is sparse; ferns, mosses, fungi & litter (0 - 2m)

TROPICAL RAINFOREST

Other Characteristics:•evergreen•hardwood•abundant species of flora & fauna; as many as 400 varieties of plants per hectare•broad leaves; thick, leathery, waxy or hairy leaves; drip tips

•shallow roots; buttress roots•colourful flowers & sweet-smelling fruits

TROPICAL RAINFOREST

TROPICAL RAINFOREST

TROPICAL RAINFOREST

TROPICAL RAINFOREST

TROPICAL RAINFOREST

TROPICAL RAINFOREST

Adaptations:} to climate

> evergreen> broad leaves

> thick leathery, waxy or waxy leaves> drip tips

Manufacture food from abundance sunlight & rain

To reduce transpiration from very high day time temp.

To drain off excess water from heavy rain to prevent fungus growth

TROPICAL RAINFOREST

Adaptations:} to soil> shallow

roots

} to competition> aerial location

> buttress root> colourful flowers & sweet-smelling fruits

To obtain nutrients from decaying litter since soil is generally infertile from leaching

To compete for sunlight given dense vegetation

To attract animals to help propagate since the air is still within dense forest

(TROPICAL) MANGROVE FOREST

Distribution:~ muddy & waterlogged; e.g. low-energy low- lying coast & river banks

Structure:

3 � horizontal zones

Nearest to the sea are trees most �tolerant of salt & flooding like avicennia & sonneratiaNext zone are trees less tolerant of salt and flooding like rhizophoraFurthest zone consists of trees least �tolerant of salt and flooding like bruguiera


Characteristics: • evergreen hardwood

• specialised roots to survive water-logged condition ~ pencil-like breathing root (avicennia) ~ prop root (rhizophora) tree-like root (bruguiera)• special salt glands in leaves • thick leathery leaves with drip tips• specialised fruits

~ elongated tube-like fruit~ buoyant fruit





TROPICAL MONSOON CLIMATE

DISTRIBUTION:


DISTRIBUTION:~ western Africa (e.g. Liberia, Ivory Coast & Ghana)

~ west coast of India

~ west coast of Thailand & Myanmar

these places have rainfall characteristics heavily influenced by monsoon winds (i.e. a distinct wet & dry season according to the specific monsoon season)


CHARACTERISTICS: Bombay ~ high mean ann. temp.

26.40C ~ high - very high mean mthly temp. 24 -

280C~ low - moderate

ann. temp. range 40C

~ high - very high ann. r/f 1855mm~ distinct wet & dry season wet season > 150 mm dry season < 100 mm


REASONS:~ High - very high ann. temp

tropical latitudes high angle of incidence direct & concentrated rays

~ low - moderate ann. temp. range those towards the subtropical

location will be affected by the ‘movement’ of Sun between Tropic of Cancer & Tropic of Capricorn higher temp. during summer mths & lower temp. during winter mths; although no true seasons experienced


REASONS:~ High - very high total ann. r/f

seasonal moisture laden winds came from sea high temp. of wind huge amt of water vapour stored

~ dry season wind blows offshore in response to

seasonal regional pressure systems dry wind ~ wet season

wind blows onshore in response to seasonal regional pressure systems wet wind


REASONS FOR WEST COAST OF INDIA:~ during the winter months (around Dec), the lower intensity & shorter duration of insolation in the temperate northern region due to the overhead Sun being at the Tropic of Capricorn very cold temp at interior Asia very high pressure system air moves out (for west coast of India) as the wind moves southward, deflection to the right due to the rotation of the Earth (Coriolis effect) NE Monsoon dry offshore wind


REASONS FOR WEST COAST OF INDIA:~ during the summer months (around July), the higher intensity & longer duration of insolation in the temperate northern region due to the overhead Sun being at the Tropic of Cancer very high temp at interior northern India very low pressure system air moves in (for west coast of India) as the wind moves northward, deflection to the right due to the rotation of the Earth (Coriolis effect) SW Monsoon wet onshore wind


REASONS FOR WEST COAST OF INDIA:

TROPICAL MONSOON FOREST

Distribution:


Distribution:

~ West coast of India

~ west coast of Myanmar

~ West coast of Central America

~ East coast of Vietnam


Structure:

~ 3 layers

~ canopy layer formed by crowns of trees; 25-30m; + epiphytes & lianas

~ ground layer consists of thick shrubs & thickets/herbs/grasses especially the start of dry season

~ understorey layer formed by shorter trees about 15m + bamboos


Other Characteristics:

~ deciduous, shed leaves at start of dry season~ dense & luxuriant vegetation during wet season, though less compared to tropical rainforest

~ many varieties of plants; about 200 varieties per hectare

~ hardwoods; like teak & rosewood

~ dense undergrowth during dry season when sunlight is able to reach the ground


Adaptations:~ deciduous reduce transpiration during dry season

~ thick leathery, waxy or hairy leaves withstand very high daytime temperature

~ deep roots tap deep groundwater, especially when water is scarce in dry season

~ drip tips prevent fungal growth & photosynthesise effectively

~ thick rough barks protection against fires in dry season

COLD/COOL TEMPERATE CLIMATE

DISTRIBUTION:

~ between 400 & 700 North only~ e.g. interior of eastern Europe (e.g. east Poland & Romania); Byelorussia; Ukraine; central Russia; much of Scandinavia (Norway; Sweden & Finland)

COLD/COOL TEMPERATE CLIMATE

CHARACTERISTICS:

~ low-very low mean annual temperature < 100C~ true seasons; spring, summer, autumn & winter~ very cold winter, with coldest mean mthly temp. <-50C~ cool summer, with warmest mean mthly temp. < 200C~ moderate to low annual precipitation; if moderate with inland location Humid Continental Cold/Cool Temperate Climate

COLD TEMPERATE CLIMATE

CHARACTERISTICS for WINNIPEG, CANADA:~ mean ann. temp 1.40C~ true seasons~ coldest mean mthly temp. (Dec) -190C~ warmest mean mthly temp. (Jul) 200C~ moderate total ann. precipitation of 555 mm; with slightly more in summer months; considered humid given continental (inland) location

COLD TEMPERATE CLIMATEEXPLANATION:

~ low mean ann. temp + true seasons high temperate latitudes (in

the 50s) small angle of incidence slanted & diffused rays low temp temperate latitudes affected by tilt of Earth’s axis variation in intensity & duration of insolation with ‘movement’ of Sun between Tropic of Cancer & Capricorn true seasons~ moderate to low precipitation

low temperature results in air having lower ability to store water vapour

low temperature causes water droplets to freeze (snow, hail & sleet)

COLD TEMPERATE CLIMATEEXPLANATION:

~ higher precipitation in summer higher temperature leads to

convectional rain

TEMPERATE CONIFEROUS FOREST

DISTRIBUTION:

~ much of Eastern Europe & Russia

~ much of Sweden & Finland

~ much of Canada & Alaska


STRUCTURE:~ single layer of conifers which grow close together to a height of about 20 metres


CHARACTERISTICS:~ evergreen conifers (straight-trunked, cone-shaped trees)

~ softwoods; e.g. fir, pine, spruce & cedar

~ needle-like leaves

~ thick barks~ very few varieties of plants; 1-2 varieties per hectare


ADAPTATIONS:

~ shedding leaves to conserve heat loss & prevent possible leaf cells damage from frost ~ thick barks to protect from low temperatures at night during winter

~ deep roots to tap deep groundwater; as surface soil moisture may freeze during winter & evaporate during summer

FOREST:

Importance:- protect against soil erosion; fertile topsoil- reduce leaching- protection of catchment area- absorption of carbon dioxide- production of oxygen- natural habitat of animals- diversity of plants/fauna- biodiversity- tribal/traditional cultures

FOREST:

Reasons for Loss of Forest:- rapid population growth; around 2%

- outflow of overcrowded cities; Rio de Janerio & Sao Paulo

- mean of subsistence living

- for commercial farming; cattle ranching, plantation cultivation of bananas, sugar cane & coffee- for mining; timber, iron ore, gold, bauxite & oil- improvement of transport; Transamazonia Highway

- for (quick easy) development

FOREST:

Measures to Save the Forest:

- control population growth

- improvement of cities’ infrastructure to cater for the growing population

- practise selective logging

- cost-benefit analysis of any econ. activities- setting aside protected areas

- setting aside tribal land reserves

- ensure sustainable development

Documents

Geography Climate and Vegetation